Because of the Ice Tower cooler, it's a bit of a chunker for a Pi. They make 2 versions, the tower and a flatter cooler, still chunk but only about 1 1/2 inch thick, The Tower is almost 2 1/2 inches tall, but it kind of fits with my Corsair Evo tower cooler on my PC.
The screws are support pieces, The corner on top is not a screw, but a plastic snap rivet for PCB boards. Have a bunch of them, allows me to pop it on and off. Thought about aluminum for the case would not need the supports. But went with the acrylic. Used a snap clip for the LED mount cover it clips to the cooler mount. Heat shrink tube for black. Slide in the acrylic tube and poof, fiber optic transfer. The Power and Act LED's on the Pi are not really bright so I can transfer the light about 6 inches max.